Investigation of the Al–Cu–Rh phase diagram in the vicinity of the decagonal phase

Abstract

Phase equilibria were studied in Al-rich Al–Rh and Al–Cu–Rh alloys. We present a partial Al–Rh phase diagram. In addition to previously reported Al–Rh phases, two complicated orthorhombic compounds were found close to the Al 3Rh composition. Partial 900 and 800°C isothermal sections of the Al–Cu–Rh phase diagram were studied in the vicinity of the decagonal phase. At these temperatures the stable decagonal phase was found to be the only ternary compound. It is in equilibrium with the ternary extensions of three binary Al–Rh phases and at 900°C also with the liquid.